This invention relates to fluid pressure regulators for use in inflation systems for inflatable escape slides and other inflatables where the output pressure of the gas supply decreases during the inflation process. This control of the increase in pressure is especially necessary and advantageous in systems where the gas under pressure is supplied to an aspirator and counteracts the increase in backpressure due to the inflation of the slide or other inflatables. If the regulator is set for optimum operation at room temperature, it does not operate satisfactorily or efficiently at low temperatures in the range of -40.degree. F. (-40.degree. C.). Therefore, it has been the practice to set the regulator for a compromise temperature which reduces the efficiency of the system at lower temperatures. The reduction in efficiency has resulted in an excessively high output pressure of the gas flow using up an excessive amount of gas and requiring a larger bottle of gas. Also the time required to deploy the inflatable has been excessive at moderate temperatures.
Another way to optimize the operation of the fluid pressure regulator is to attach a temperature compensator containing a fluid to the regulator whereby the fluid is expandable and contractible in response to increase or reduction of temperature of the gas, thereby optimizing the operation of the regulator. However, such a regulator is susceptible to loss of fluid, reducing the effectiveness of the temperature compensator and the operation.
A further way to adjust pressure has been to use a temperature compensator having an internal rubber plug which by expanding or contracting due to temperature changes, controls the pressure output of the regulator valve. However, in this instance the rubber plug suffers from the fact that it is compressible and subject to "creep" under load over a time period. This condition shows up as requiring an extended deployment time for the escape slides, which condition is unacceptable to the customer and to the safety of the passengers who are to use the slides in the case of an emergency. It is an object of the present invention to use a bimetallic device as a temperature compensator which utilizes the different rate of thermal expansion of the two different metals to adjust the position of the regulator valve. A further feature of the present invention is to provide several tubes of different diameters nested in parallel relationship to give the equivalent of a single tube assembly within one-third of the actual effective length that would be required in this instance.